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  • image The population of people 65 years and older is increasing.

  • image Age-related changes in physiology affect the functions of various organ systems and contribute to the onset of diseases.

  • image Age-related changes in physiology can affect the pharmacokinetics and pharmacodynamics of numerous medications.

  • image Successful aging is determined by individually defined measures of well-being that include maximizing health span and socio-environmental engagement.


Preclass Engaged Learning Activity

Brainstorm a list of age-related changes that occur in the human physiology and the effects they may have on pharmacokinetics/pharmacodynamics of medications in older adults.


Medications can cure or palliate medical conditions in older adults, however, they can also cause a number of drug-related problems. Prevention of drug-related problems requires that health professionals be knowledgeable about the changes that occur with aging and the implications this has on prescribing, monitoring, and evaluating medication regimens in older adults. This chapter will focus on the epidemiology of aging, mechanisms of aging, physiologic changes due to aging with an emphasis on the age-related changes in pharmacokinetics and pharmacodynamics of medications, and successful aging to maximize health span and quality of life.


image The proportion of persons 65 years and older is increasing worldwide. In 2015, the percentage of people 65 years and older in the world was 8.5% and is projected to increase to 16.7% in 2050. In the United States, the population of older adults has changed from a pyramidal shape to a pillar. The rectangular shape will be top heavy in 2050 due to the baby boomer population. In 2015, 14.9% of the population was considered geriatric in the United States, and in 2050 it is projected to be 22.1%.1 In 2035, the older adult population will outnumber children under 18 years old for the first time in US history.2

The population is aging due to people having fewer children and living longer. In the United States, the life expectancy in 2014 at birth for men is 76.4 years and 81.2 years for women. At age 65 and 85 years old, respectively, men are projected to live an additional 18 and 5.9 years, compared to 20.5 and 7 years for women.3 The US life expectancy is down for the second year in a row from 78.7 in 2015 to 78.6 years in 2016. This may be attributed to an increase in drug overdose deaths and suicide rates in younger adults.4

Older adults often have multiple chronic conditions and thus need to see a number of specialists and healthcare providers. In 2013 to 2014, the highest reported chronic health conditions in the United States for adults 65 and older were hypertension (55.9%), arthritis (49%), heart disease (29.4%), cancer (23.4%), diabetes (20.8%), asthma (10.6%), chronic bronchitis or emphysema (8.1%), and stroke ...

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